: I'd really like to see the whole paragraph, since "kick in the ass" can have more than one meaning. If you're translating into Italian you'll have to know; "un calcio nel sedere" is probably pretty meaningless in Italy. In the sentence above, it makes a difference who did the kicking and who got kicked. It CAN mean nothing more than "shocker," something that causes one to look on in shock or react with shock. It can mean to shock or prod someone into activity, or better activity, by giving them the metaphorical kick in the ass. (Nancy Pelosi intends to kick the ass of the FCC.) It may mean punishment or just meanness. I'm sure you won't confuse it with the meaning in such sentences as "She kicked ass," or "Do that again, and I'll kick your ass."
: SS
: Obviously you know best what phrase in Italian will convey the same meaning and tone.

There's an old Dean Martin song called "Ain't That a Kick in the Head?" about a guy who's suddenly fallen in love and he feels like he got kicked in the head. I suppose it's just as shocking whether you get kicked in the head or the ass, or somewhere else, but they couldn't say "ass" and still get played on the radio back in Dean Martin's day. I bet if you find a Dean Martin fan who speaks Italian (and there are a lot of them--try looking for a fan forum on the internet) they'd be happy to provide a rough translation.